The present invention pertains to a vehicular safety system and method, and, in particular, to a vehicular safety system and method for preventing injury to the passenger of a motorized vehicle by separating a body support from the ground contacting assembly of the vehicle.
Vehicles, whether for the transportation of humans or other types of payloads, may lack stability, either by design or due to the nature of their use. Many such vehicles are particularly susceptible to tipping, whether due to collision, mechanical failure, sudden turns, steep inclines, or an encounter with a surface irregularity for which the mechanism is incapable of compensating. Indeed, any personal vehicle may tip when sufficiently severe surface irregularities are encountered. Under these circumstances, the occupant or contents of the vehicle must be protected so that injury does not result from propulsion of the occupant toward the ground or other solid obstacle. Unless protected, the occupant may also sustain injury due to trauma or crushing if the vehicle, which is relatively massive, overturns or is propelled, due to its inertia, into a solid obstacle or on top of the occupant.
Methods are known for absorbing or diverting kinetic energy inherent in the motion of a vehicle to insure that it is not converted to propulsion of the occupant of the vehicle into a solid body such as the ground. Common examples are bumpers on cars, which absorb kinetic energy in crumpling metal, and airbags, which couple the mechanical energy of car passengers into the compression and redistribution of gas in a bag before enough time has elapsed for the bodies of the passengers to hit the steering wheel or windshield of the car with resulting serious injury.
Other means are known to employ the kinetic energy present in a massive subcomponent of the vehicle, to inflate a bellows or other cushion to protect the vehicle occupants in the case of a head-on collision.
In an unenclosed vehicle such as a wheelchair, for example, it is often safer to divert the passenger from the path of the center of mass of the vehicle than to trap him between the mass of the vehicle, moving with its attendant momentum, and its ultimate position of repose, such as at a solid surface after a crash.
In accordance with one aspect of the invention, in one of its embodiments, there is provided a safety mechanism for protecting a passenger of a vehicle in a situation wherein the vehicle undergoes undesirable acceleration. The vehicle is one which has a ground contacting assembly and a body support with a center of gravity (CG). The safety mechanism has a connector for coupling the body support and the ground contacting assembly. It also has a release for decoupling the motion of the CG of the body support along at least one axis from the motion of the ground contacting assembly. An actuator for unleashing the release in response to an undesired acceleration of the vehicle is also provided.
In accordance with an alternate embodiment of the invention, the connector allows free motion of the body support with respect to the ground contacting assembly, and may be a pneumatic cylinder or a slide track. The safety mechanism may also have a rotary actuator, including a motor, for rotating the body support with respect to the ground contacting assembly such as to counteract the effect of a roll of the ground contacting assembly on the orientation of the body support with respect to a vertical direction.
In other embodiments of the invention, the safety mechanism has a pilot wheel assembly coupled to the body support. The pilot wheel assembly may include at least one wheel, and a self-leveling mechanism. The release may include a means for storing mechanical energy, such as a spring or torsion spring, coupled to at least one of the ground contacting assembly and the body support such that the mechanical energy is used to decouple the motion of the CG of the body support from the motion of the ground contacting assembly.
In accordance with further embodiments of the invention, the safety mechanism may have a reservoir of mechanical energy coupled to at least one of the ground contacting assembly and the body support such that the mechanical energy is used to decouple the motion of the CG of the body support from the motion of the ground contacting assembly.
In accordance with another aspect of the invention, a method is provided for protecting a passenger of a vehicle having a ground contacting assembly and a body support in a situation wherein the vehicle undergoes undesirable acceleration. The method has the steps of sensing the undesired acceleration and decoupling the motion of the center of gravity of the body support from the motion of the ground contacting assembly with respect to at least one axis.